CANCER ANAEMIA 



603 



also observed to have an increased aldolase content in the plasma^"'*^ 

 Phosphatases^"^^ and lactic acid dehydrogenase^^^^ have been Ibund, among 

 others, at enhanced concentrations in cancerous plasma. Factors 

 present in cancerous plasma may not exclusively be responsible for 

 the curtailment of the life-time of red corpuscles. The R. E. system, 

 which presumably plays only a more or less passive role in the uptake- 

 of erythrocytes which have reached the physiological end of their exis- 

 tence, can be activated in the neoplastic organism and can act upon the 



o Kontroll 

 • Tumor 



• • 



10 



15 



20 



25 



Tage 



Fig. 5. Liver weights of control and tumour-bearing mice. 

 Kontrol — control; Tumor — tumour, Tage — days. 



red corpuscles. In healthy human beings red corpuscles have an approx- 

 imately constant life-time of 100—120 days and when this has been 

 attained they are taken up by the R.E. system. P. MiEscHER^^'^Mias sought 

 for ^^Cr in the organs of rabbits into which ^^Cr-labelled red corpuscles 

 had been transfused 25—35 days previously. He found the greatest 

 concentration of ^UJr in the bone marrow, with the liver and spleen 

 next in order. It might be argued against these results that the ^^Cr is 

 not firmly bound in the red corpuscles, that it escapes from the intact 

 erythrocytes, and therefore an enrichment of ^^Cr in an organ can be 

 attributed to causes other than the decay of red corpuscles in the organ 

 concerned. Experiments performed in our laboratory by Ehrenstein 

 and LocKNER^^^\ with transfused erythrocytes which had been labelled 

 with ^^Fe, showed a very similar result. Haemoglobin, so long as it is 

 embedded in the intact erythrocyte, is among the most stable compounds 

 present in the animal body and ^^Fe can escape from it only after damage 

 to the erythrocyte. In the experiments mentioned above, the plasma of 

 the acceptor-sister animal was inactive and ^^Fe was present only in 

 the transfusing erythrocytes. The ^^Fe which they were able to detect 



